NSC 655649, a Rebeccamycin analog, is an antibiotic with antitumor properties originally isolated from the actinomycete strain Saccharothrix acrocolonigenes. Its parent compound, rebeccamycin, was found to have activity against P388 leukemia, L1210 leukemia and B16 melanoma implanted in mice. It also inhibits the growth of human lung adenocarcinoma cells and has been shown to be a strong DNA interclator with in vivo and in vitro antitumor activity. The objectives of this study are (1) to determine the maximum tolerated dose of rebeccamycin analogue when administered as five consecutive daily doses every 3 weeks; (2) to determine the pharmacokinetic parameters of rebeccamycin analogue; and (3) to observe patients for clinical antitumor response after rebeccamycin analogue.